A conventional rock breaking apparatus comprises a hydraulically operated piston-cylinder assembly, a slider wedge which is reciprocable by means of a piston rod connected to the piston of the piston-cylinder assembly, and presser checks which are insertable in holes drilled in rock and have heads which are attached to the cylinder of the piston-cylinder assembly and bearing surfaces engageable with the outer surfaces of the slider wedge so as to be laterally movable on reciprocation of the slider wedge to split the rock.
Apparatus constructed in this manner can generate breaking or splitting forces of the order of magnitude of 300 tons, and more, so as to enable clumps of rock, concrete parts or the like to be split and comminuted without the use of explosives. In spite of the large splitting forces generated, the diameter of the apparatus, in the vicinity of the presser cheeks, is only of the order of magnitude of 45 mm, and so the necessary drill holes can be made inexpensively.
It has been found to be advantageous to releasably connect the presser cheeks and/or the slider wedge to the piston-cylinder assembly so that, if necessary, these parts, which are subjected to high loads, can be replaced. Also, it is often desired to replace slender presser cheeks by presser cheeks of thicker dimensions when, after the rock or concrete has been opened up, it is necessary to broaden the gap formed. Thus, under these circumstances replacement usually takes place at the work site or quarry and for this reason, should be simple and quick to effect.